Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Mechanical Engineering

Dynamic Properties Of Railway Track And Its Components : A State-Of-The-Art Review, Sakdirat Kaewunruen, Alexander Remennikov Nov 2011

Dynamic Properties Of Railway Track And Its Components : A State-Of-The-Art Review, Sakdirat Kaewunruen, Alexander Remennikov

Alex Remennikov

Recent findings indicate one of major causes of damages, which is attributed to the resonant behaviours, in a railway track and its components. Basically, when a railway track is excited to generalised dynamic loading, the railway track deforms and then vibrates for certain duration. Dynamic responses of the railway track and its components are the key to evaluate the structural capacity of railway track and its components. If a dynamic loading resonates the railway track’s dynamic responses, its components tend to have the significant damage from excessive dynamic stresses. For example, a rail vibration could lead to defects in rails …


Analytical Comparison Of Multimicrophone Probes In Measuring Acoustic Intensity, Curtis P. Wiederhold Aug 2011

Analytical Comparison Of Multimicrophone Probes In Measuring Acoustic Intensity, Curtis P. Wiederhold

Theses and Dissertations

In the late 1970s, a method was developed to estimate acoustic intensity in one dimension by taking the cross-spectral density of two closely-spaced microphone signals. Since then, multimicrophone probes have been developed to measure three-dimensional intensity as well as energy density. Their usefulness has led to the design of various types of multimicrophone probes, the most common being the four-microphone orthogonal, the four-microphone regular tetrahedron, and the six-microphone designs. These designs generally either consist of microphones suspended in space near each other or mounted on the surface of a sphere. This work analytically compares the relative merits of each probe …


Quantifying Multiple Types Of Damping Acting On Bronze-Wound Guitar Strings, Jonathan Christian Jun 2011

Quantifying Multiple Types Of Damping Acting On Bronze-Wound Guitar Strings, Jonathan Christian

Purdue Polytechnic Masters Theses

The goal of this study was to quantify the contributions of multiple damping types acting on guitar strings for each mode over a wide frequency range so that design variables could be identified to one day create frequency based damping in guitar strings. Structural dynamic testing was used to obtain the time-response of a vibrating string in open air and in a vacuum. From this signal, each harmonic was filtered and the decay envelope was curve-fitted with a function that was a linear summation of decay functions. From the curve-fits, the damping coefficients for aerodynamic, friction, and material damping were …


The Effect Of Static Pressure On The Inertial Cavitation Threshold And Collapse Strength, Kenneth Bryan Bader Jan 2011

The Effect Of Static Pressure On The Inertial Cavitation Threshold And Collapse Strength, Kenneth Bryan Bader

Electronic Theses and Dissertations

The amplitude of the acoustic pressure required to nucleate a gas and/or vapor bubble in a fluid, and to have that bubble undergo an inertial collapse, is termed the inertial cavitation threshold. The hydrostatic dependence of the inertial cavitation threshold was measured up to 30 MPa in ultrapure water using a high quality factor spherical resonator. The threshold increased linearly with the hydrostatic pressure and was found to be temperature dependent. The strength of the bubble collapse at the threshold was measured in terms of shock waves and light emissions. The shock amplitudes increased linearly with the hydrostatic pressure, while …